This invention relates to a driving gear for all-wheel-drive vehicles, and more particularly to a driving gear for all-wheel-drive vehicles, comprising a reduction gear meshed with an output gear in a transmission, a planetary gear type interaxle differential gear arranged concentrically with the reduction gear so as to output the driving force therefrom into front and rear interwheel differential gears in a divided manner, a driving shaft provided through and concentrically with the interaxle differential gear so as to transmit one output therefrom to one of the two interwheel differential gears, and a driving gear member mounted on said driving shaft so that the driving gear member can be rotated relatively thereto, so as to transmit the other output from the interaxle differential gear to the other interwheel differential gear. An object of the present invention is to provide a driving gear for all-wheel-drive vehicles, which is capable of carrying out the shifting of the distribution of torque to the front and rear wheels of a vehicle very easily by replacing a small number of parts thereof.
According to the present invention, the interaxle differential gear consists of a planetary carrier mounted rotatably on the driving shaft on the side of a driving gear member so as to form a clearance between the planetary carrier and the driving shaft, a support member mounted rotatably on the driving shaft so as to be opposed to the planetary carrier, and a ring gear, pinions and a sun gear which are provided between the planetary carrier and support member, a connecting member which joins the ring gear and driving shaft or driving gear member together being provided between the pinions and support member or planetary carrier, the driving shaft being provided with a spline for joining the connecting member or sun gear thereto, the driving gear member being provided with a hub formed integrally therewith, extending from the clearance into the interaxle differential gear and having a connecting portion joined to the sun gear or connecting member, the reduction gear being formed unitarily with the planetary carrier and support member.